/Engine/Source/Editor/Sequencer/Public/IKeyArea.h
Add a key at the specified time with the current value of the channel, updating an existing key if possible
A handle to the key that was added or updated
[FKeyHandle](API\Runtime\Engine\Curves\FKeyHandle) AddOrUpdateKey ( [FFrameNumber](API\Runtime\Core\Misc\FFrameNumber) Time, const [FGuid](API\Runtime\Core\Misc\FGuid) & ObjectBindingID, [ISequencer](API\Editor\Sequencer\ISequencer) & InSequencer )